This was one of the most challenging assignments. So many little things can throw this off. If you are not in edit mode, and using the correct type of parenting, offset, or bone, etc. The same thing when assigning color, make sure you are in edit mode or pose mode!! Making sure the hierarchy of parenting is important too of course. Good job to all for working on this one.
Hi Xavier,
I've been trying to respond to your other question but the system hasn't let me for whatever reason (it's silly).
It looks like you have it solved, although I can't see the YT video because...well YT is being silly)
But this is what I noticed from your other question.
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That's a dependency cycle, Xavier.
It looks like the Aim bone is parented to the base bone, but the base is targeting the Aim with a damped track.
This is an issue because the parent is trying to point towards the child, but the child is being moved by the parent. So they are stuck in an infinite loop.
The solution is to parent the Aim to the Root.
(I can also see that you have accidentally renamed the armature to "base" - this happens when you rename in object mode rather than pose mode)
Don't worry - this is all part of your learning.
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I hope it still helps - although I think you overcame your issues and grew your knowledge along the way. Well done.